What I've learned

MLA

Edward W. Nelson. “What I’ve Learned.” The American Journal of Surgery, vol. 202, Dec. 2011, pp. 623–31. EBSCOhost, https://doi.org/10.1016/j.amjsurg.2011.07.005.

APA

Edward W. Nelson. (2011). What I’ve learned. The American Journal of Surgery, 202, 623–631. https://doi.org/10.1016/j.amjsurg.2011.07.005

Chicago

Edward W. Nelson. 2011. “What I’ve Learned.” The American Journal of Surgery 202 (December): 623–31. doi:10.1016/j.amjsurg.2011.07.005.